Painting machine



March 27, 1962 c. G. MARTIN ET AL PAINTING MACHINE 4 Sheets-Sheet 1 Filed Dec. 8, 1958 INVENTORS CLYDE G. MARTIN LEO T- M HUE BY $(MM%MZZ9M ATTORNEYS March 27, 1962 Filed Dec. 8, 1958 LO LO C. G. MARTIN ETAL PAINTING MACHINE 4 Sheets-Sheet 2 INVENTORS CLYDE G. MARTIN LEO T. M HUE AT TOR EYS March 27, 1962 c. e. MARTIN ET AL 3,025,343

PAINTING MACHINE Filed Dec. 8, 1958 4 Sheets-Sheet 3 INVENTORS C E G. RTIN L T.M E

ATTOR EYS March 27, 1962 c. G. MARTIN ET AL PAINTING MACHINE 4 Sheets-Sheet 4 Filed Dec. 8, 1958 ow mm mm wm 6 mm 8 mm g mm mm 2 wZDO wQw FIOE Oh CLYDE G. MARTIN LEO T. M HUE .m LN

United States Patent @fiice 3,fi26,843 Patented Mar. 27, 1962 3,026,843 PAINTING MACHINE Clyde G. Martin and Leo T. McHue, Toledo, Ohio, as-

siguors to Conforming Matrix Corporation, Toledo, Ohio, a corporation of Ohio Filed Dec. 8, 1958, Ser. No. 778,674 16 Claims. (Cl. 118-313) This-invention relates to automatic spray painting apparatus of the type which paints articles by meansof spray guns and metal electroformed masking shields that confine the paint accurately to desired patterns.

The economical repetitious painting of like articles demands automatic spray painting machines which do not require the attendants to do anything other than to place the articles to be painted in the machines and to remove them after they have been painted.

It is desirable that such a painting machine have a low initial cost, have a rugged construction which holds up well in the field, have a high production painting cycle, be completely automatic yet be under the control of the attendant, have the flexibility to accept articles to be painted of various shapes and sizes, and produce work of the highest quality. With all of this, it is necessary that the machine be completely safe to operate and be easy to load and unload. It is highly desirable that such attend ant is able to load articles to be painted into the machine and unload the finished articles out of the machine continuously with little or no time lost while waiting for the machine to go through any part of its automatic cycle.

It is, accordingly, the principal object of this invention to provide apparatus for automatically applying a coating compound to an article (or articles) while a finished article (or articles) is being removed from the apparatus and replaced byanother to be coated so that an attendant is able to unload and load the machine continuously with little or no time lost while waiting for the machine to apply the coating compound.

Another object of the invention is to provide apparatus for automatically spraying a coating compound onto an article supported by holding means in juxtaposition with a form-fitting, stencil-like mask, the holding means automatically moving the article into such position and being interlocked With the spraying means to prevent spraying of the coating compound before the article is so positioned.

Another object is to provide in such apparatus a holder for such form-fitting, stencil-like mask which will easily accommodate masks of various sizes.

A further object is to provide, in apparatus for automatically spraying a coating compound by means of a reciprocating sprayer onto an article in juxtaposition with a form-fitting, stencil-like mask, selectively controlled means for automatically rocking such sprayer so that it is oriented to direct coating compound onto all of the surface of an irregularly shaped article.

Still another object is to provide, in apparatus for automatically spraying a coating compound onto a plurality of articles by means of a plurality of reciprocating sprayers, a single prime mover means for reciprocating such plurality of sprayers to greatly simplify the construction and to greatly increase the efi'iciency of the apparatus.

A further object is to provide a multiple fixture automatic painting machine which fixtures automatically move articles to be painted from loading positions into juxtaposition with form-fitting, stencil-like masks and automatically return such articles after they are painted to such loadingv position, it being. possible for an attendant to load articles onto such fixtures and remove them therefrom easily and safely.

Another object is to provide an automatically variable rate drive means for such fixtures whereby the articles to be painted are moved relatively slowly from the loading positions into juxtaposition with the form-fitting, stencil-like masks so that little or no damage occurs should an article to be painted be misaligned with its form-fitting mask and are returned relatively swiftly after they are painted to such loading positions to increase the productivity of the machine.

Other objects and advantages will be apparent from the following description in which reference is had to the accompanying drawings:

According to the invention, apparatus is provided for automatically applying coating compounds to articles, such apparatus being exemplified by a double fixture painting machine. One of the fixtures automatically moves an article to be coated from a loading position into juxtaposition with a form-fitting, stencil-like mask which article is sprayed automatically while an attendant removes a coated article from the other fixture while it is in its loading position and replaces it with an article to be coated. The fixtures and the spraying means are so interlocked that no spraying occurs unless an article to be coated is properly positioned at its mask. This enables the attendant to unload coated articles from and to load articles to be coated into the machine continuously without time being lost while he is waiting for spraying to take place. The coating compound is applied by means of a plurality of sprayers which are reciprocated in straight paths adjacent the masks by means of a single prime mover. Optionally, the sprayers may be rocked automatically at the ends of the paths so that they are oriented to direct their spray onto all of the surfaces of irregularly shaped articles.

A preferred embodiment is illustrated in the accompanying drawings.

In the drawings:

FIG. I is a view in perspective of the multiple fixture automatic painting machine of the invention;

FIG. II is an enlarged, fragmentary front elevational view of the upper part of the machine which is illustrated in FIG. I with the three doors shown at the top of such machine in FIG. I removed to reveal interior details;

FIG. III is a plan view as seen from a position along line IIIHI of FIG. II looking in the direction indicated by the arrows;

FIG. IV is an enlarged and detailed view of part of the machine as seen in FIG. II illustrating certain elements in different positions, a portion being shown in vertical section;

FIG. V is an enlarged and detailed view of one of the mask holders which is illustrated in FIG. I; and

FIG. VI is a schematic pneumatic diagram showing the operation of the machine.

These specific figures are intended merely to illustrate the invention but not necessarily to limit its scope.

The multiple fixture automatic painting machine of the invention includes a cabinet 1 (FIG. I) partially enclosing a left hand application station or area 2 and a right hand application station or area 3. The application areas 2 and 3 are defined by a rear wall 4, side walls 5, and the top of a work table 6, a partition 7 separating the areas.

Articles to which coating compounds are to be applied are supported in the application areas 2 and 3 on work holding means 8. Specifically, such articles as shown for the purpose of illustration are toy automobiles 9 one of which can be seen in the right hand application area 3. Each of the work holding means 8 includes a work holder 10 which is formed by being cast inside a toy automobile 9 and then finished until the automobile 9 is easy to fit over the holder and is easy to remove, but which has a tight enough fit to hold the automobile securely during the various operations of the machine. The cast part of such work holder 10 is secured to a base 11 which is held by means of screws 12 on an adapter 13 that is secured to the very end of a piston rod 14, the adapter 13 being shown in FIG. I and being removed from the piston as shown in FIG. V to reveal such end of the piston rod 14. Each of the piston rods 14 is an operative part of an air cylinder 15 which is secured in a vertical position to the underneath side of the work table 6 with its piston extending through the table into its application area. Access to the cylinders 15, there being one below each of the application areas 2 and 3, is obtained through an opening in an end of the cabinet 1 that normally is closed by a door 16. Part of the cabinet 1 below the application area 2 is broken away in FIG. I to reveal one of the cylinders 15 and its adjuncts.

If it is desired to apply decorating compound to only certain patterns on the articles, the cabinet 1 is provided with metal electroformed masking shields, i.e., formfitting, stencil-like masks 17, detachably mounted on adjustable mask holders 13, there being a mask 17 located directly above each one of the work holders 1%. Each one of the masks 17 has an opening 19 which, when an automobile 9 is fitted within the mask as shown in the left hand application area 2, permits coating compound to be sprayed through the mask onto the roof of the automobile, the rest of the automobile being masked off. The stroke of each of the piston rods 14 is such that in the retracted position of the rod as shown in the right hand application area 3 the work holder 10 is in a convenient position to be unloaded and/or loaded and in the extended position of the rod as shown in the left hand application area 2 the work holder 11 holds the article 9 to be coated in the form-fitting, stencil-like mask 17, i.e., in juxtaposition with the mask.

One of the mask holders 18 is shown in detail in FIG. V; it comprises a base 20 that is secured to the top of the work table 6 and that includes aplurality of threaded holes 21, and a pair of legs 22 which are so adjustably secured to the base 20 by means of screws 23 which are threaded into the holes 21 that the legs 22 are positionable to selectively widen or narrow the space between the legs. A horizontally grooved guide 24 is mounted at the upper end of each of the legs 22 and a latch bar 25 is removably secured to the guides 24 in a position which is parallel to the base 2! Screws 26 hold the latch bar 25 on the guides 24, the screws 26 being placed in those of the holes 27 in the latch bar 25 which happen to be aligned with the guides 24. Apertured blocks 28 are spaced along the latch bar 25 and are spaced just far enough below a lower surface 29 of the latch bar so that the back edge of the mask 17 can be received snugly between the blocks 28 and such lower surface 29. The aperture 30 in each of the blocks is aligned with a corresponding hole 31 in the latch bar 25. The grooved guides 24 are adapted to receive the side edges of the mask 17 which is slid into the mask holder 18 until its back edge is positioned between those of the apertured blocks 28 that are located between the guides 24 and the lower surface 29 of the latch bar 25. Pins 32 then are thrust through the aligned holes 31 and 30 of the mask holder 18, there being corresponding holes in the mask 17 to also receive such pins to hold the mask 17 in place. By adjusting the position of the legs 22 along the base 20 the mask holder 18 is adapted to accommodate masks 17 of various widths. The pins 32 are shown in their operative positions in FIG. I.

In the general operation of the painting machine, the mask holders 13 are adjusted to hold suitable masks 17 which are securely held by the holders 18 above the Work holders 10 that are adapted as hereinbefore described to detachably hold the particular articles to be coated. The work holders 10 can be removed from the piston rods FIG. I.

14 by loosening screws 33 which fix the adapters 13 to the ends of the piston rods.

When one of the piston rods 14 is in its extended position, the other one always is in its retracted position. The attendant unloads the article 9 which has been painted from that one of the work holders 10 which is in its leading (retracted) position and replaces it with an article to be painted. He then manipulates the operating lever 34 of a valve 35 at the partition 7. Operation of the valve 35, as hereinafter described in detail in connection with FIG. VI, causes the piston rods 14 to reverse their positions, the newly loaded one of the piston rods advancing its work holder 10 along with the article 9 to be painted thereon into its mask 17 and the other one of the piston rods lowering its work holder 10 along with the freshly painted article 9 thereon into its unloading position. The automatic means for spray coating or painting the articles is described hereinafter. As shown in FIG. I, the left hand one of the piston rods 14 is extended and has lifted the article 9 into a juxtaposed position relative to its mask 17 ready to be painted and the right hand one of the piston rods 14 is retracted and has lowered the freshly painted article 9 into unloading position. The attendant then repeats the procedure by unloading the freshly painted article and replacing it with one to be painted and again operating the lever 34 of the valve 35.

The automatic means for spray painting the articles 9 includes a pair of conventional spray guns 36 in each of the application areas 2 and 3. Each pair of guns 36 is secured to a rod 37 that is carried by a lever 38 which is fulcrumed to rock on a shaft 39 mounted in a bearing bracket 40 only the bottom part of which is visible in The rest of the brackets 40 and means for reciprocating and rocking the guns 36 are hidden behind doors 41 in FIG. I, two of such doors being shown shut and one being shown open. Such means is shown in detail in FIGS. IiIV. The spray guns 36 are positioned on the rods 37 so that each one directs its spray toward the surface to be painted and so that the spray from each pair completely covers the surface it is spraying upon. Suitable exhaust equipment filters and discharges fumes through a stack which communicates with discharge ports 42 in the rear wall 4 of the cabinet 1 to maintain an atmosphere free from coating or painting compounds.

Referring to FIGS. II-IV, each of the brackets 40 is secured by means of screws 43 to the bottom of a carriage 44 which is slidably mounted on a pair of track rods 45, bushings 46 in the carriage serving to receive the rods 45. The track rods extend the full width of the cabinet 1 and are suitably supported at the side walls 5 and are large enough to form a rigid track for the two carriages 44 to be reciprocated upon. Immediately above the bracket 40 is an opening 47 in the bottom of the carriage 44 through which the lever 38, which is fulcrumed in the bracket, extends, the opening 47 being large enough to permit the lever 38 to be rockable about the axis of the shaft 39.

An air cylinder 48 is hung by means of angle brackets 49 from the top of the cabinet 1 and its piston rod 50 is fixed to a pair of continuous chains 51, an angle bracket 52, which is connected to the piston rod 50 by means of a pair of nuts 53 threaded on the end of the piston rod 50 and which is connected by means of bolts 54 to the chains 51, serving to join the piston rod 50 and the pair of chains 51 so that the piston rod and the chains move together as one. Each of the continuous chains 51 extends between idler sprockets 55, there being a pair of sprockets 55 at each of the side walls 5 of the cabinet 1. Each of the pairs of sprockets 55 is mounted on a shat t 56 which is journaled at its ends in bearings 57 atop blocks 58 that are on a horizontal shelf 59 (FIG. I) of the cabinet 1.

Each of the two carriages 44 includes a horizontal bottom plate 60 in which the opening 47 is formed and to which the bracket 40 is attached and a pair of vertical side plates 61 extending upwardly therefrom in which the bushings 46' are mounted. A pair of back and front plates 62 are attached to the plates 63 and 61 and each of these supports an arm '63 one of which is secured to the lower flight of one of the continuous chains 51 and the other one of which is secured to the lower flight of the other one of the continuous chains 51, washer members 63a and bolts 64 serving to connect the arms 63 and the chains 51. Hence, movement of the piston rod 50 to the left (extended position) as viewed in FIGS. II and III moves the upper flights of the continuous chains 51 to the left and the lower flights of the chains 51 to the right and, therefore, both of the carriages 44 to the right, i.e., both of'the carriages 44 move as one with the piston rod 50 but in the opposite direction; As shown in FIGS. II and III, the piston rod Sit is in its retracted position and the carriages 44 are in non-spraying positions at the left hand sides of their respective application areas 2 and 3 of the cabinet 1. The air cylinder 43 serves use single prime mover for the two pairs of spray guns 36' operatively connected thereto. This is a low cost and efiicient means for reciprocating the guns. The two pairs of spray guns 36' could, of course, be increased to any reasonable number. The painting machine could be provided with additional application areas and more guns could be strung on the continuous chains 51 to operate in such additional application areas.

The vertical side plates 61 of each of the carriages 44 also function to support a pair of adjustment screws 65 the ends of which are opposed, the screws being locked in adjusted positions by means of nuts '66. The opposed ends of the adjustment screws 65 function to limit the rocking of the spray guns carrying levers 3-8 about the axes of the fulcrum shafts 39. As shown in FIG. II, the adjustment screws 65 are tightened up to prevent any rocking of the levers 38 at all, while as shown in FIG. IV, the adjustment screws 65 are so positioned that the lever 33 can rock from its position shown in solid lines to its position shown in broken lines.

The vertical side plate 61 of each of the carriages 44 additionally function to carry a pair of air cylinders 67 having piston rods 68 the ends of which are opposed. When it is desired to rock the spray guns carrying levers 38, the respective piston rods 68 are caused to be ex tended and retracted as hereinafter described in connection with FIG. VI, and they rock the levers against the adjustment screws 65 as illustrated in FIG. IV. Hence, the spray guns 36 are reciprocated in straight paths adjacent the masks 17 by the extension and retrac- 9 tion of piston rod 50 and are rocked about the axes of fulcrum shafts 39 by the extension of the respective piston rods 68.

One of the vertical side plates 61 of each of the carriages 44 additionally functions to carry an arm 69 which has a cam 70 detachably secured to its free end. Each of the two cams 70 is arranged to contact the operating roller 71 of a normally closed valve '72, which is in the trigger air lines for its pair of spray guns 36 as hereinafter described, when the guns are reciprocated. The valves 72 are adjustably mounted on a strut 73 carried by the shelf 59 of the cabinet 1, each of the valves 72 being attached by means of screws 74 to a plate 75 which when the screws 74 are loosened is slidable behind wings 76 of the strut but which when the screws 74 are tightened is drawn up against such wings 76 to clamp the valve securely in place. Thus, when screws 74 are loosened the valves 72 can be positioned along the strut 73 and When the screws 74 are tightened the valves retain their adjusted positions. Struts 77, one of which is shown in FIG. I, which are like strut 72 are located one adjacent each of the two air cylinders 15. Each of the struts 77 carries a lower 73 and an upper 79 normally closed valve, such valves being positionable along struts 77 in the same way that valves 72 are positionable along strut 73. Valve 78 is provided with an operating roller and valve 79 is provided with an operating roller 81 which rollers 80 and 81 are operated by a cam 82 that is carried up and down in a vertical path by a rod 83'which extends up through the table 6 and which is operatively connected to the end of the piston rod 14- by means of a plate 84 (FIG. V) which is secured to a cylindrical member 35 fixed to the end of the piston rod 14. Thus, the two piston rods 14 and the two cams 82 move up and down as'one.

The guns 36 automatically spray from above and upon the articles 9 to be coated which are underneath the masks 17. The apparatus, of course, could be reversed with the guns spraying from beneath and against articles on top of the masks. The guns 36 spray the coating compounds with blasts of-atomizing air supplied from a header or surge tank 86' (FIG. VI) charged with compressed air from a suitable source through a line 87 which first takes the air through a gate valve 88 and a filter 89. The header 86 can be drained through a line 99 communicating with a valve 91.

The atomizing air for the right hand guns 36, as seen in FIGS. I and VI, flows from the header 86 through a line 92 to an air regulator 93 controlled by a knob 94 and connected to a gauge 95. As indicated in FIG. VI, the line 92 may supply a plurality of right side guns. The knob 94 may be turned to various positions to regulate the flow of atomizing air to the guns. Similarly, the atomi'zing air for the left hand guns 36 flows from the header 86 through a line 96 to an air regulator 97 controlled by a knob 98 and connected to a gauge 99. As indicated in FIG. VI, the line 96 may supply a plurality of left side guns. The knob 98 may be turned to various positions to regulate the flow of atomizing air to the guns. The knobs 94 and 98 and the gauges and 99 are mounted for easy access on the front of the cabinet 1 (FIG. I).

Air to operate the work holder cylinders 15 is supplied from the header 86 through an air line lubricator 100 to the four-way valve 35 which is operated by its manually controlled operating lever 34 as hereinbefore described, such lever 34 and valve 35 being shown in FIG. I and in FIG. VI. Movement of the operating lever 34 in one direction causes air to flow through the valve 35 into a line 101 and movement of the operating lever 34 in the opposite direction causes air to flow through its valve 35 into a line 102. When air flows into the line 101, air is exhausted from the line 102 through a port 103 of the valve 35 and when air flows into the line 102, air is exhausted from the line-161 through a port 104 of the valve 35. It is assumed for the present purpose of illustration that the air flow is into the line 101. Air flow through the line 101 is into an air regulator 105 having a manually operated controlling knob 106 and a gauge 107, such knob 106 and gauge 107 being mounted on the front of the cabinet 1 (FIG. I).

From the regulator 105, air flows through a quick exhaust valve 108 to the left hand work holder cylinder 15 to extend its position rod' 14 in opposition to the return spring 109 within the cylinder. The work holder It? and the cam rod 83 which have been described hereinbefore are shown schematically in FIG. VI connected to the piston rod 14. The quick exhaust valve 108 provides immediate passage through its exhaust port 110 to the atmospherefor any back pressure tending to hinder the motion of the piston rod 14, i.e., it provides for dumping of exhaust air directly to the atmosphere for rapid piston action. The rate of return of the piston rod 14 is determined by the size of the orifice at the bottom of the cylinder 15. This arrangement causes the piston rod 14- to be moved relatively slowly to its extended position so that should the article 9 be painted be misaligned with its form-fitting mask 17 little or no damage will accur and Causes the piston rod 14 to be moved rapidly to its retracted position to increase the productivity of the ma- 7 chine. As soon as the valve 35 is reversed by the attendant and air exhausts from the line 101 through the port 104 of the valve 35, the air within the left hand cylinder 15 is dumped directly to the atmosphere through the exhaust port 110 of the quick exhaust valve 108 and the return spring 109 within the cylinder 15 then rapidly retracts the piston rod 14 to move the work holder into its loading position.

The left hand guns 36 in application area 2 are controlled by triggers operated by compressed air flowing from the header 86 through a line 111 to an air regulator 112 having a manually operated controlling knob 113 and a gauge 114, such knob 113 and gauge 114 being mounted on the front of the cabinet 1 (FIG. 1). Air flowing from the regulator 112 is the machine air for the apparatus which operates various of the operating parts of the machine. Trigger air for the left hand guns 36 flows from the regulator 112 through a main line 115 and a branch line 116 to a normally open pilot valve 117 which normally is held open by means of a spring 118. A pilot valve which is operated by air in one direction and by a spring in the other direction is shown in detail in FIG. VI in U.S. Patent No. 2,795,206 issued on June 11, 1957, to E. L. Faber. However, when the left hand work holder piston rod 14 is in its retracted position so that the work holder 10 is in its loading position the cam on the cam rod 83 operates the roller 80 (also see FIG. I) of the lower normally closed valve 78 to hold the valve 78 open. This is the position of the left hand cam rod 83 which is shown in broken lines in FIG. VI. Air flow to the valve 78 is from the main line 115 through a branch line 119 and air flow out of the valve 78 to the pilot valve 117 is through a line 120. When the valve 78 is held open, air flow through the line 120 to the pilot P of the pilot valve 117 holds the normally open pilot valve 117 closed in opposition to its return spring 118. This prevents trigger air flow out of the pilot valve 117 through a line 121 to the left hand guns 36.

When the left hand work holder piston rod 14 is extended, as shown in solid lines in FIG. VI, the normally closed valve 78 is closed. In fact as soon as the work holder piston rod 14 starts to move upward, the cam on the cam rod 83 moves out of contact with the operating roller 80 of the normally closed valve 78 and the valve closes. Closing of the valve 78 cuts off the flow of air through the line 120 to the pilot P of the pilot valve 117 and the spring 118 then opens the valve. Trigger air then flows from the branch line 116 through the valve 117 and through the line 121 to the left hand normally closed valve 72 (see FIGS. II and III) where it stands ready to trigger such guns 36 when the operating roller 71 of the valve 72 is moved by the corresponding cam 70 by the reciprocation of the guns 36 as hereinafter described.

When the left hand work holder piston rod 14 is ex tended and the article 9, therefore, is in position to be spray coated, as shown in solid lines in FIG. VI, the cam on the cam rod 83 is in contact with the operating roller 81 of the upper normally closed valve 79 (also see FIG. I) and holds the valve 79 open. Air then flows from the main line 115 through a branch line 122, the now open valve 79, a line 123, a check valve 124, and through an ordinary cutout valve 125. Cutout valves conventionally are used in any air system where a fixed quantity of air is to be passed on each cycle. The instant the given amount of air has passed through a cutout valve, it cuts out and prevents any additional air from passing until the air ahead (upstream air) of the cutout valve is exhausted. The given amount of air that passes through the cutout valve (downstream air) must be exhausted by some other means before another cycle can be started. Excess air which flows from the check valve 124 after the cutout valve 125 has closed is exhausted through a bleeder valve 126 which communicates with a muffler 127 to silence such exhaust.

The fixed quantity of air that is passed by the cutout valve flows through a bleeder valve 128 having an atmosphere exhaust port 129 to a 4-way double pilot valve 130 which is supplied with machine air by the main line 115 and which is provided with exhaust ports 131 and 132. This operates differential pilot K of the valve 130 and air flows from the line 115 through the valve 130 and into a line 133 and air exhausts from a line 134 through the port 131 of the valve 130. Air flows from the line 133 through a flow control valve 135 having a manually operated control knob 136 to the right hand end of the air cylinder 48 (also see FIGS. II and III) and through a quick exhaust valve 137, which is like the quick exhaust valve 108 except that the valve 137 is provided with a bleeder valve 138 that adjusts the rate of the exhaust to the atmosphere from a port 139 of the valve 138, to the right hand ones of the pairs of air cylinders 67, the quick exhaust valve 137 and the right hand one of the left hand pair of the air cylinders 67 being connected by means of a line 140 and the quick exhaust valve 137 and the right hand one of the right hand pair of the air cylinders 67 being connected by means of a line 141. This moves the piston rods of such three cylinders to the left, i.e., to their extended positions.

Extension of the piston rods 68 of the right hand ones of the pairs of air cylinders 67 rocks the spray guns carrying levers 38 counterclockwise about the axes of the shafts 39 against the adjustment screws 65. One of the levers 38 is illustrated in this position in FIG. IV. This tilts the spray guns 36 at an angle toward the masks 17 so that as the guns are shifted from left to right in the application areas 2 and 3 as viewed in FIG. I the spray impinges upon all of the surfaces of irregularly shaped articles. For example, if instead of painting the roofs of the toy automobiles 9 as illustrated in FIG. I, the bodies of such automobiles were being painted, the spray from the tilted guns would hit partially hidden spots such as those underneath the hoods over the headlights. The degree of such tilt depends upon the adjusted positions of the screws 65 (FIG. IV). There is thus provided selectively controlled means for automatically rocking the spray guns so that they are properly oriented to direct coating compound onto all of the surfaces of irregularly shaped articles. However, not all articles to be painted are irregularly shaped. For example, only the roofs of the automobiles 9 are sprayed through the openings 19 in the masks 17 as illustrated in FIG. I. Such roofs are simple surfaces which do not require rocking of the guns 36 for complete coverage. Therefore, the guns 36 as shown in FIG. I are not rocked but are only reciprocated back and forth over the articles 9 to be painted. The guns are locked in center positions by tightening up the adjustment screws 65 as illustrated in FIG. 11. Hence, it is optional whether or not the guns are rocked, FIG. II showing how the guns are locked so as not to rock and FIG. IV showing how the guns are rocked between limits that are determined by the adjustment screws 65.

As about the same instant that the extension of the piston rods 68 of the right hand ones of the pairs of air cylinders 67 rocks the spray guns carrying levers 38 counterclockwise, the extension of the piston rod 50 of the air cylinder 48 begins to occur. Movement of the piston rod 50 to its extended position, i.e., to the left as viewed in FIG. VI, causes the movement of both of the carriages 44 which carry the air cylindres 67, the guns 36, and the cams 70 to the right as hereinbefore described. When the cams 70 contact the operating rollers 71 of the normally closed valves 72, the valves open and trigger air passes through the left hand valve 72 to trigger the left hand guns 36, however, nothing happens at the right hand guns 36 because as hereinafter described no trigger air is being supplied to the right hand valve 72 during this part of the cycle. Spraying of coating compound continues as long as the cams 70 hold the normally closed valves 72 open.

The operating roller 142 of a normally closed valve 143 is positioned in the path of the piston rod 50 of the air cylinder 48. This roller is shown schematically in FIG. VI and as it actually appears in FIGS. II and III, the angle bracket 52 on the piston rod 50 being the element which actually contacts the roller 142 and operates the valve 143. Opening of the normally closed valve 143 permits machine air to flow from the main line 115 through a branch line 144 and through the valve 143 and a line 145 to the 4-way double pilot valve 130. This operates pilot P of the valve 130 and air flows from the line 115 through the valve 130 and into the line 134 and air exhausts from the line 133 through the port 132 of the valve 136. Air flows from the line 134 through a flow control valve 146 having a manually operated control knob 147 to the left hand end of the air cylinder 48 to reverse the piston 50 and through a quick exhaust valve 148, which is like the quick exhaust Valve 137 and that is provided with a bleeder valve 149 which adjusts the rate of the exhaust to the atmosphere from a port 151 to the left hand ones of the pairs of air cylinders 67, the quick exhaust valve 148 and the left hand one of the left hand pair of the air cylinders 67 being connected by means of a line 151 and the quick exhaust valve 148 and the left hand one of the right hand pair of air cylinders 67 being connected by means of a line 152. This moves the piston rods of such three cylinders to the right.

Extension of the piston rods 68 of the left hand ones of the pairs of air cylinders 67 rocks the spray guns carrying levers 38 clockwise about the axes of the shafts 39 against the adjustment screws 65, return springs 153 within the opposite cylinders 67 retracting their piston rods 63 as soon as the pilot valve 130 is reversed so that air is exhausted from such cylinders 67 through the quick exhaust valve 137 that is connected to such cylinders by means of the lines 146 and 141. Similar return springs 154 within the left hand ones of the pairs of air cylinders 67 retract their piston rods 68 when the pilot valve 136 is so operated that air exhausts from the line 134 through the port 131 of the valve 130 so that air is exhausted from such cylinders 67 through the quick exhaust valve 148 that its connected to such cylinders 67 by means of the lines 151 and 152.

At about the same instant that the extension of the piston rods 68 of the left hand ones of the pairs of air cylinders 67 rocks the spray guns carrying levers 38 clockwise, the reversal of the piston rod 50 of the air cylinder 48 begins to occur. Movement of the piston rod 50 to its retracted position, i.e., to the right as viewed in FIG. V1, causes movement of both of the carriages 44 which carry the air cylinders 67, the guns 36, and the cams 70 to the left. Movement of the cams 70 to the left causes them to contact the operating rollers 71 of the normally closed valves 72 to again hold such valves open. Hence, the left hand guns 36 spray on both their forward and return strokes as they are reciprocated, no spraying of the right hand guns 36 occurring on either stroke because as hereinafter described no trigger air is being supplied to the right hand valve 72 during this part of the cycle. Spraying of coating compound continues as long as the cams 70 hold the normally closed valves 72 open.

When the piston rod 50 is completely retracted and the carriages 44 are back to their original positions the cycle is complete and nothing happens again until the attendant manipulates the operating lever 34 of the valve 35. In this position of the carriages the normally closed valves 72 are closed and the guns 36 no longer spray. In the position of the apparatus as illustrated in FIG. VI,

the pilot valve is supplying air to the left hand end of the air cylinder 48 to reverse the piston rod 50 and is supplying air to the left hand ones of the pairs of air cylinders 67 which have just rocked the guns 36 clockwise to tilt them at an angle toward the masks 17 so that as the guns are shifted from right to left in the application areas 2 and 3 the spray impinges upon all of the surfaces of irregularly shaped articles. The length of the spraying time is controlled by the widths of the cams 70. The widths of the cams 71) can be changed to adjust the spraying time if the cams are of the adjustable type or cams of different widths can be substituted to produce the desired spraying time. The length of the stroke of the air cylinder 48 is adjusted by varying the position of the valve 143 which valve causes the cylinder to reverse as soon as the operating roller 142 of the valve 143 is operated by the piston rod 56 of the air cylinder 48. The speed of the piston rod 50 of the air cylinder 48, i.e., the rate of reciprocation of the chain driven carriages 44 which carry the spray guns 36, is controlled by the flow control valves and 146 which are controlled in turn by their manuaily operated knobs 136 and 147, respectively.

During the time that the guns 36 are reciprocated and rocked at the ends of their paths and while the left hand guns 36 are spraying coating compound upon the article 9 in the mask 17, in application area 2, the attendant removes the freshly coated article 9 from the right hand work holder 10 in application area 3 and replaces it with another to be coated. Just as soon as the painting cycle in the application area 2 has been completed, he again manipulates the operating lever 34 of the valve 35 which is conveniently located at the partition 7 of the cabinet 1. The length of the painting cycle depends on the requirements of the work such as the size and shape of the article to be painted and upon the characteristics of the coating compound. In any event, the painting machine with its double fixtures and completely automatic operation increases the productivity of an attendant by as much as 70 to 100 percent or more as compared to any known machine. The double fixture automatic painting machine of the invention automatically applies a coating compound to an article (or articles) while a finished article (or articles) is being removed from the apparatus and replaced by another to be coated so that the attendant is able to unload and load the machine continuously with little or no time lost while waiting for the machine to apply the coating compound. The machine is safe to operate and is easy to load and unload and is under the complete control of the attendant because after every painting cycle it comes to a stop until he reverses the operating lever 34 of the valve 35. This lever 34 may be formed as a foot pedal and be located on the floor for foot operation if this is found desirable.

When the attendant reverses the operating lever 34 of the valve 35, air flows into the line 102 and air is exhausted from the line 161 through the port 1114 of the valve 35. Air flow through the line 102 is into an air regulator having a manually operated controlling knob 156 and a gauge 157, such knob 156 and gauge 157 being mounted on the front of the cabinet 1 (FIG. I).

From the regulator 155, air flows through a quick exhaust valve 153 having an exhaust port 159, which quick exhaust valve 153 is like and functions like the quick exhaust valve 168, to the right hand work holder cylinder 15 to extend its piston rod 14 in opposition to a return spring 160 within the cylinder. At the same time, the return spring 109 within the left hand cylinder 15 rapidly retracts its piston rod 14 to move its work holder 10 into its loading position as hereinbefore described.

The right hand guns 36 in application area 3 are controlled by triggers operated by compressed air flowing from the air regulator 112 through a main line 161 and a branch line 162 to a normally open pilot valve 163 which normally is held open by means of a spring 164. The pilot valve 163 is like and functions like the pilot valve 117. However, when the right hand work holder piston rod 14 is in its retracted position, as illustrated in FIG. VI, the cam on the cam rod 83 operates the roller 80 of the lower normally closed valve 78 to hold the valve 73 open. Air flow to such valve 78 is from the main line 161 through a branch line 165 and air flow out of the valve 78 to the pilot valve 163 is through a line 166. When the valve 78 is held open, air flow through the line 166 to the pilot valve 163 holds the normally open pilot valve 163 closed in opposition to its return spring 164. This prevents trigger air flow out of the pilot valve 163 through a line 167 to the right hand guns 36.

When the right hand work holder piston rod 14 is extended, the normally closed valve 78 is closed. In fact as soon as the work holder piston rod 14 starts to move upward, the cam on the cam rod 33 moves out of contact with the roller 80 of the normally closed valve 78 and the valve closes. Closing of the valve 78 cuts off the flow of air through the line 166 to the pilot P of the pilot valve 163 and the spring 164 then opens the valve. Trigger air then flows from the branch line 162 through the valve 163 and through the line 167 to the right hand normally closed valve 72 where it stands ready to trigger the right hand guns 36 when the operating roller 71 of the valve 72 is moved by the corresponding cam 70 by the reciprocation of such gums 36.

When the right hand work holder piston rod 14 is extended and the article 9, therefore, is in position to be spray coated, the cam on the right hand cam rod 83 is in contact with the corresponding operating roller 81 of the upper normally closed valve 79 and holds the valve open. Air then flows from the main line 161 through a branch line 168, the now open valve 79, a line 169, a check valve 170, and through the hereinbefore described cutout valve 125. The cutout valve 125 again passes the fixed quantity of air to the 4-way double pilot valve 130 and the piston rod 50 of the cylinder 48 again is reciprocated to reciprocate the spray guns 36 and the piston rods 63 of the cylinders 67 again are operated to rock the spray guns 36. When the right hand cam 70 holds the corresponding roller 71 of the normally closed valve 72 open the right hand guns 36 spray. Hence, the right hand guns 36 spray on both their forward and return strokes as they are reciprocated, no spraying of the left hand guns occurring on either stroke because no trigger air is being supplied to the left hand valve 72 during this part of the cycle. When the piston rod of one of the work holder cylinders is retracted the piston rod of the other one of the work holder cylinders 15 always is extended and vice versa. Although both sets of spray guns 36 are reciprocated and rocked during each cycle, only the set of guns corresponding to the extended one of the piston rods 14 of the work holder cylinders 15 is supplied with trigger air so that it is able to spray. Therefore, only one of the two sets of guns sprays during each cycle. After every cycle, when the piston rod 59 of the cylinder 48 is retracted and the carriage 44 are back to their original positions everything stops until the attendant reverses the lever 34 of the valve 35.

The controlling of the trigger air for each set of spray guns 36 by means of a plurality of valves provides interlocks which are another one of the features of the painting machine. The interlocks prevent spraying of the guns 36 until the article 9 to be sprayed is up within its mask 17 ready to be sprayed. Two events must occur before either one of the two sets of guns 36 can spray. First, a work holder 10 must move upwardly to allow its corresponding normally closed valve 73 to close the closing of which permits the corresponding normally open pilot valve to open and allow flow of trigger air to the corresponding normally closed valve 72. This conditions such valve 72 so that it stands supplied with trigger air. Second, such work holder 16 must move completely upward to position the article 9 carried thereby into its mask 17 ready to be sprayed before anything else can happen.

CJI

When the work holder 10 moves completely upward, the corresponding normally closed valve 79 is opened the opening of which permits air to flow to the 4-way double pilot valve whereby the spray guns 36 and the cams 7 l are reciprocated. Reciprocation of the cams 70 causes them to open both of the normally closed valves 72, only the conditioned one of which passes trigger air to its set of spray guns 36.

In operation, the attendant manipulates the lever 34 of he valve 35. One of the work holder piston rods 14 then is extended slowly and the other one of the work holder piston rods 14 is retracted rapidly and the two sets of guns 36 are reciprocated. The set of guns 36 which corresponds to the extended one of the work holder piston rods 14 sprays on both the forward and return strokes. At the end of the cycle everything comes to a halt. After unloading and loading the retracted one of the work holders, the attendant reverses the valve 35. This causes the work holder piston rods 14 to reverse their positions. Again the two sets of guns 36 are reciprocated and again the set of guns which corresponds to the extended one of the work holder piston rods 14 sprays on both the forward and return strokes. Optionally, the guns can be made to automatically rock at the ends of the paths in which they are reciprocated.

Various modifications may be made in specific details of construction without departing from the spirit and scope of the invention.

Having described the invention, We claim:

1. Apparatus for applying coating compounds to articles, said apparatus comprising, in combination, a plurality of reciprocably mounted work holders, means for reciprocating each of the work holders in a rectilinear stationary path between a loading position and a coating position, each of the work holders having its own separate loading and coating position, said means, whenever it moves one of the work holders into its loading position, positioning another one of the work holders in its coating position, and applying means for applying coating compounds to articles on the work holders.

2. Apparatus for applying coating compounds to articles according to claim 1 wherein said applying means includes a single prime mover and a chain drive for reciprocating the applying means.

3. Apparatus for applying coating compounds to articles, said apparatus comprising, in combination, a plurality of reciprocably mounted work holders, means for reciprocating each of the Work holders between a loading position and a coating position, said means, whenever it moves one of the work holders into its loading position, positioning another one of the work holders in its coating position, said means being adapted to move the work hold ers into their loading positions at a rate of speed which is higher than the rate of speed at which it moves the work holders into their coating positions, and applying means for applying coating compounds to articles on the work holders.

4. Apparatus for applying coating compounds to articles, said apparatus comprising, in combination, a plurality of reciprocably mounted work holders, means for reciprocating each of the work holders in a rectilinear path between a loading position and a coating position, said means, whenever it moves one of the work holders into its loading position, positioning another one of the work holders in its coating position, applying means associated one with each one of the work holders for applying coating compounds to articles supported by the work holders, and interlock means for preventing operation of every applying means during the time that its work holder is not in its coating position.

5. Apparatus for applying coating compounds to articles, said apparatus comprising, in combination, a plurality of form-fitting, stencil-like masks which confine the coating compounds accurately to desired patterns on the articles, means for stationarily supporting each of the masks that is adjustable to accommodate masks of various sizes, a work holder for each of the masks, each work holder being mounted to move between a loading position and a coating position and being adapted to carry an article from the loading position into the coating position wherein such article is in juxtaposition with its mask and from the coating position back into the loading position, reciprocating means for moving the work holders in rectilinear paths, said reciprocating means, whenever it moves one of the Work holders into its loading position, positioning another one of the work holders in its coating position, and applying means for applying coating compounds to. articles on thework holders.

6. Apparatus for applying coating compounds to articles, said apparatus comprising, in combination, a plurality of stationarily mounted form-fitting stenciLlike masks which confine the coating compounds accurately to desired patterns on the articles, work holders one for each of the masks, each work holder being mounted to move between a loading position and a coating position and being adapted. to carry. an article from the loading position into the coating, position wherein such article is in juxtaposition with its mask and from the coating position back into the loading position, reciprocating means for moving the work holders in rectilinear paths, said reciprocating means, whenever it moves one of the work holders into its loading position, positioning another one of the work holders in its coating position, applying means associated one with each one of the Work holders for applying coating compounds to articles on the work holders, and interlock means for preventing operation of every applying means during the time that its work holder is not in its coating position.

7. Apparatus for applying coating compounds to articles comprising, in combination, a plurality of work holders each mounted to move back and forth in a single path between a loading position and a coating position, means for moving the work holders into and out of such positions, a stationarily mounted track, carriage associated one with each one of the work holders reciprocably mounted on the track, applying means rockably mounted one on each of the carriages for applying coating compounds to articles supported by the work holders, means for automatically reciprocating the carriages every time that the means for moving the work holders is operated, and means for automatically rocking the applying means at each end of the paths in which they are reciprocated.

8. Apparatus for applying coating compounds to articles comprising, in combination, a plurality of work holders each mounted to move between a loading position and a coating position, means for moving the work holders into and out of such positions, a stationarily mounted track, carriages associated one with each one of the work holders reciprocably mounted on the track, applying means mounted one on each of the carriages for applying coating compounds to articles supported by the work holders, means for automatically reciprocating the carriages every time that the means for moving the work holders is operated, means for operating the applying means during at least part of the time that they are reciprocated, and means for preventing operation of any of the applying means unless the work holder associated therewith is in its coating position.

9. Apparatus for applying coating compounds to articles comprising, in combination, a plurality of work holders each mounted to move between a loading position and a coating position, means for moving the work holders into and out of such positions, a stationarily mounted track, carriages associated one with each one of the work holders reciprocably mounted on the track, pneumatic applying means rockably mounted one on each of the carriages for applying coating compounds to articles supported by the work holders, means for automatically reciprocating the carriages every time that the means for moving the work holders is operated, means for supplying air only to those of the applying means for operation which happen to be associated with work holders that are out of their loading positions, and means for operating the applying means when they are. reciprocated and when the work holders associated therewith are in their coating positions.

10. Apparatus for applying coating compounds to articles comprising, in combination, a plurality of work hold.- ers each mounted to move back and forth in a single path between a loading position and a coating position, means for moving the work holders into and out of such positions, a stationarily mounted track, carriages associated. one with each one of the work holders reciprocably mounted on the track, applying means rockably mounted one on each of the carriages for applying coating compounds to articles supported by the work holders, means for automatically reciprocating the carriages every time that the means for moving the work holders is operated, means for automatically rocking, the applying means at each end of the paths in which they are reciprocated, and adjustable means for limiting rocking of the applying means.

11. Apparatus for applying coating compounds to articles comprising, in combination, a plurality of work holders each mounted to move between a loading position and a coating position in a single path, means for moving the work holders into and out of such positions which are adapted to move the work holders into their loading positions at a rate of speed which is higher than the rate of speed at which the work holders are moved into their coating positions, a stationarily mounted track, carriages associated one with each one of the work holders reciprocably mounted on the track, applying means mounted one on each of the carriages for applying coating compounds to articles supported by the work holders, and means for automatically reciprocating the carriages every time that the means for moving the work holders is operated.

12. Apparatus for applying coating compounds to articles comprising, in combination, a plurality of reciprocably mounted work holders, means for reciprocating each of the work holders in a rectilinear path between a loading position and a coating position, said means whenever it moves one of the work holders into its loadcompounds to articles supported by the work holders, in its coating position, applying means associated one with each one of the work holders for applying coating compounds to articles supported by the Work holders, and means for automatically reciprocating the applying means every time that the means for reciprocating the work holders is operated.

13. A double fixture automatic painting machine comprising, in combination, means defining first and second application areas, a reciprocably mounted work holder in each one of the areas, means for reciprocating each of the work holders between a loading position and a coating position, said means always positioning one of the work holders in its coating position when it positions the other one of the work holders in its loading position, at least one spray gun in each of the areas for applying coating compounds to articles on the work holders, and means for automatically reciprocating all of the guns substantially horizontal planes whenever either one of the Work holders reaches its coating position.

14. A double fixture automatic painting machine comprising, in combination, means defining first and second application areas, a reciprocably mounted work holder in each one of the areas, means for reciprocating each of the work holders between a loading position and a coating position, said means always positioning one of the work holders in its coating position when it positions the other one of the work holders in its loading position, at least one spray gun in each of the areas for applying coating compounds to articles on the work holders, means for automatically reciprocating all of the guns whenever 1 5 either one of the work holders reaches its coating position, and means for automatically rocking the guns at the ends of the paths in which they are reciprocated.

15. A double fixture automatic painting machine comprising, in combination, means defining first and second application areas, a reciprocably mounted work holder in each one of the areas, means for reciprocating each of the work holders between a loading position and a coating position, said means, whenever it positions one of the work holders in its coating position, positioning the other one of the work holders in its loading position, at least one spray gun in each of the areas for applying coating compounds to articles on the work holders, means for automatically reciprocating all of the guns whenever either one of the work holders reaches its coating position, interlock means for conditioning those of the spray guns for operation which happen to be associated with the work holder which is in its coating position, and cams which move as one with the reciprocating guns for causing operation of the conditioned ones of the spray guns during at least part of the time that they are reciprocated.

16. A double fixture automatic painting machine comprising in combination, means defining first and second application areas, a reciprocably mounted work holder in each one of the areas, means for reciprocating each of the work holders between a loading position and a coating position, said means always positioning one of the work holders in its coating position when it positions the other one of the work holders in its loading position, at least one spray gun in each of the areas for applying coating compounds to articles on the work holders, means for automatically reciprocating all of the guns whenever either one of the work holders reaches its coating position, and interlock means for preventing operation of a gun during the time that the work holder with which such gun is associated is not in its coating position.

References Cited in the file of this patent UNITED STATES PATENTS 691,075 Rigaud Jan. 14, 1902 1,185,889 Eberhart June 6, 1916 1,347,256 Davis July 20, 1920 1,831,535 Juers Nov. 10, 1931 1,932,215 Johnson et a1. Oct. 24, 1933 1,959,711 Flint et a1. May 22, 1934 2,141,630 Westin Dec. 27, 1938 2,267,273 Garbe Dec. 23, 1941 2,390,457 Pearson et a1 Dec. 4, 1945 2,401,047 Burns et a1. May 28, 1946 2,434,125 Schweitzer Jan. 6, 1948 2,434,176 Potthofl Jan. 6, 1948 2,442,179 Shanklin et al. May 25, 1948 2,512,581 Palermo June 20, 1950 2,574,675 Walker Nov. 13, 1951 2,610,605 Paasche Sept. 16, 1952 UNITED STATES PATENT OFFICE CERTIFICATION OF CORRECTION Patent No. .0 3 March 27,1962

Clyde G. Martin et al.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 5, line 72, for "72" read 73 column 6 line 59 for "position" read piston line 72, for "9 be" read 9 to be column 8, line 62, for "As" read At line 69, for "cylindres" read cylinders column 11 line 57, for "carriage" read carriages column 14 line 43, after "means" insert a comma; line 45, strike out "compounds to articles supported by the work holders," and insert instead ing position, positioning another one of the work holders line 62, after "guns" insert 'in Signed and sealed this 23rd day of October 1962.

(SEAL) Attest:

ERNEST W. SWIDER DAVID L. LADD testing Officer Commissioner of Patents 

